CVE-2026-35031 Details
Jellyfin is an open source self hosted media server. Versions prior to 10.11.7 contain a vulnerability chain in the subtitle upload endpoint (POST /Videos/{itemId}/Subtitles), where the Format field is not validated, allowing path traversal via the file extension and enabling arbitrary file write. This arbitrary file write can be chained into arbitrary file read via .strm files, database extraction, admin privilege escalation, and ultimately remote code execution as root via ld.so.preload. Exploitation requires an administrator account or a user that has been explicitly granted the "Upload Subtitles" permission. This issue has been fixed in version 10.11.7. If users are unable to upgrade immediately, they can grant non-administrator users Subtitle upload permissions to reduce attack surface.
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Exploit prediction scoring system (EPSS) score for CVE-2026-35031
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.4 Probability of exploitation activity being observed over the next 30 days (61st percentile)
CVSS score for CVE-2026-35031
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
9.9 Critical
Products affected by CVE-2026-35031
Jellyfin 10.11.1
Jellyfin 10.11.2
Jellyfin 10.11.3
Jellyfin 10.11.4
Jellyfin 10.6.4
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
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CVE-2026-35031 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 268 43.44%
DE 51 8.27%
FR 44 7.13%
HR 41 6.65%
CA 21 3.40%
AU 19 3.08%
NL 16 2.59%
ES 15 2.43%
GB 14 2.27%
RU 12 1.94%

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CVE-2026-35031 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Telecommunications 340 73.75%
Technology 109 23.64%
Education 5 1.08%
Engineering 3 0.65%
Government/Politics 3 0.65%
Energy/Resources 1 0.22%

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